Dark Chocolate May Boost Brain Function, Immunity, And Mood

Studying the brain benefits of chocolate—cocoa and dark chocolate, mainly—has become a big area in recent years. Numerous studies have suggested that high-potency cacao has significant effects on things like cognition, mood, cholesterol, insulin sensitivity, and blood vessel function. Now, two new studies from Loma Linda University find that some of chocolate’s benefits may also occur at fairly doable doses: A serving or two of dark chocolate may boost memory, cognition, the immune system, and mood.

Both studies were presented this week at the Experimental Biology 2018 annual meeting this week.

For one study, the researchers had healthy participants eat the equivalent of a chocolate bar—48 grams of dark chocolate, which was 70% cacao and 30% organic cane sugar. Then their brains were scanned with EEG, which measures brain waves, 30 minutes and 60 minutes after eating the chocolate. The team reports that gamma waves increased across multiple areas of the cortex, mainly related to cognition and memory; the changes were much more robust at the earlier time point, and largely returned to normal at the later one.

In the second study, participants ate the same variety of chocolate as above, every day for a week. They were asked to abstain from high-antioxidant foods in the days leading up to the study. Their blood was collected every day after they’d eaten the chocolate, so that the researchers could measure the expression of multiple genes.

It turned out that genes involved in the immune response (e.g., white blood cell activation) were boosted, while those involved in inflammation were reduced. The expression of genes involved in neural signaling and sensory perception also increased.

The results might be encouraging for people looking for more evidence to support their predilection for dark chocolate.

“For years, we have looked at the influence of dark chocolate on neurological functions from the standpoint of sugar content - the more sugar, the happier we are," said study author Lee Berk in a statement.

Well, this isn’t exactly true, since researchers have been attributing the neurological benefits of cocoa to its polyphenols (antioxidants) for years. Universities have been studying cocoa for a long time, and Mars, Inc. has helped fund studies to quantify the effects of flavanols, and measure their effects on both cognition and the brain. In one Columbia University study, participants who drank a high-potency flavanol drink for three months had improved memory function and changes in a part of the brain linked to age-related memory decline. Other studies have shown similar results on cognition and memory.

But what may be more noteworthy about the new studies is that they suggest it may not take huge amounts of bitter chocolate or super-condensed cocoa to have measurable effects. "This is the first time that we have looked at the impact of large amounts of cacao in doses as small as a regular-sized chocolate bar in humans over short or long periods of time, and are encouraged by the findings," says Berk. “These studies show us that the higher the concentration of cacao, the more positive the impact on cognition, memory, mood, immunity and other beneficial effects.”

The studies were both very small pilot studies, and neither has been published in a peer-review journal, which means that they should be considered preliminary.

But because earlier work has found similar connections, it’s not difficult to imagine that the new studies’ findings are valid. So if you're a fan of dark chocolate, science again suggests you may carry on.